Wednesday’s events on the fifth floor of the county’s Government Center were stunning – even for this county.

District Attorney Michael A. Ramos and California Attorney General Edmund G. “Jerry” Brown Jr. announced the arrests of Bill Postmus, the former county supervisor and assessor, and Jim Erwin, the former assistant assessor and chief of staff to a county supervisor, on charges of accepting bribes to provide votes for a legal settlement that transferred $102 million from county taxpayers to Colonies Partners L.P., the developers of the Colonies in Upland.

Of course, those two and three others, including Rancho Cucamonga Councilman Rex Gutierrez, were already facing criminal charges related to misdeeds in the Assessor’s Office.

But the criminal complaint made public Tuesday implicates not only Postmus, but also Supervisor Paul Biane and the chief of staff of Supervisors Chairman Gary Ovitt. Postmus, Biane and Ovitt approved the Colonies settlement by a 3-2 vote.

The complaint does not name Biane, but alleges that “John Doe #5,” who “… was a member of the Board of Supervisors of San Bernardino County,” “joined the conspiracy by agreeing to accept a bribe to vote to approve the Colonies settlement.” The complaint asserts that on Nov. 28, 2006, “Postmus and John Doe #5, along with Ovitt,” voted to approve the settlement. No. 5 can be no one but Biane.

Another unnamed party is John Doe #4, described as “Chief of Staff for a member of the Board of Supervisors,” who the complaint alleges “accepted a bribe of $100,000 from Colonies for delivering the vote of Ovitt.”

Sure, San Bernardino County has seen more than its share of corruption, including a supervisor who resigned six years ago in a bribery scandal.

We’ve reported extensively on shaky if not shady practices in county government. We ran a story and a large chart showing that, in the wake of the Colonies settlement, Colonies Partners contributed $100,000 to each of four PACs controlled by Postmus, Erwin and the chiefs of staff of Biane and Ovitt.

Still, it’s stunning when the district attorney and attorney general allege that two supervisors and a third supervisor’s chief of staff accepted bribes in return for betraying every single county taxpayer.

“The object of the conspiracy was to illegally obtain $102,000,000 from the County, for personal gain, and for certain public officials to share in those gains by forsaking their solemn duties and responsibilities to the County and the citizens they served, in violation of their oaths of office and the laws of the State of California,” the criminal complaint sums up.

Again, wow.

Bear in mind, of course, that nothing is proved. Postmus and Erwin have been charged, while five John Does – two of them each described as “a General Partner of Colonies Partners, L.P.” – have not even been charged, but are alleged in the complaint to have committed crimes as part of a bribery conspiracy. All are innocent until proven guilty.

Even so, county voters and taxpayers have to be appalled at the mere possibility that their elected representatives have used them as the DA and AG allege.